Orbi or Powerline

If you're living in a condo or apartment, I'd probably avoid powerline unless your devices are on the same exact circuit. 

Reason I say this is powerline is sensitive to interference and apartments/condo's tend to have quite a bit of interference from sketchy devices on the power system. I haven't had much luck in getthing them working decently on seperate circuits in apartments. 

The other issue is orbi. It might work great for you. It might not as many things can impact wireless performance. Lots of apartments/condos are made with brick walls. Which block wifi great. Plus there tends to be a lot of signals from everyone having their own wifi. which creates interference. 

And trying to use a single satellite and not the router will only work with the RBS40V and the RBS50Y. They're the only 2 orbi satellites that have extender mode and don't "need" the primary router. The other systems all need a router to control it. 

so do we have an answer that will 100% fix your problem? no. 

What I'd do is buy your setup from somewhere with a generous return policy so you can try the system and see how it works. If it works great, use it. If it doesn't, bring it back and try something else.